我正在动态调用Windows API。我在网上发现了一些可以做到这一点的代码，我对此非常感兴趣。至少可以说，这个想法本身就很棒。但是，我似乎无法使其适用于我的代码。动态调用的参数类型为string，string int[]，我希望使用参数GetThreadContext的API pInfo.hThred和ref ctx（如下所示）。
API致电
GetThreadContext(pInfo.hThread, ref ctx);
上面的代码将调用GetThreadContext API（假设它在我的项目中声明） - 并且工作得很好。然而，动态调用的美妙之处在于不需要声明。所以，我尝试动态调用：
ctx = new CONTEXT {ContextFlags = 0x10007};
PROCESS_INFORMATION pInfo;
CInvokeAPI.Invoke("kernel32","GetThreadContext",pInfo.hThread, ctx);
这里的问题是我不知道如何将参数ctx作为类型int传递，因为它是一个结构体。
请参阅下面的其他代码
[StructLayout(LayoutKind.Sequential)]
struct CONTEXT
{
public uint ContextFlags;
unsafe fixed byte unused[160];
public uint Ebx;
public uint Edx;
public uint Ecx;
public uint Eax;
unsafe fixed byte unused2[24];
}
[StructLayout(LayoutKind.Sequential)]
struct PROCESS_INFORMATION
{
public IntPtr hProcess;
public IntPtr hThread;
public int dwProcessId;
public int dwThreadId;
}
调用API动态类
using System;
using System.Runtime.InteropServices;
using System.Text;
/*
* Title: CInvokeAPI.cs
* Description: Call API by name implementation in purely managed C# (no 'unsafe' mess here).
*
* Developed by: affixiate
* Comments: If you use this code, I require you to give me credits.
*/
public static class CInvokeAPI
{
/// <summary>
/// Generates a new, non-garbage collectable string in memory. Use this with Unicode "W" API.
/// </summary>
/// <param name="theString">A Unicode string.</param>
/// <returns>Address of newly allocated string in memory. Remember to free it after use.</returns>
public static int StringToPtrW(string theString)
{
return StringToPtr(Encoding.Unicode.GetBytes(theString));
}
/// <summary>
/// Generates a new, non-garbage collectable string in memory. Use this with ANSI "A" API.
/// </summary>
/// <param name="theString">An ANSII string.</param>
/// <returns>Address of newly allocated string in memory. Remember to free it after use.</returns>
public static int StringToPtrA(string theString)
{
return StringToPtr(Encoding.ASCII.GetBytes(theString));
}
/// <summary>
/// Internal method used to allocate memory.
/// </summary>
/// <param name="buf">A byte buffer.</param>
/// <returns>Address of newly allocated memory. Remember to free it after use.</returns>
private static int StringToPtr(byte[] buf)
{
return (int)GCHandle.Alloc(buf, GCHandleType.Pinned).AddrOfPinnedObject();
}
/// <summary>
/// Invokes the specified Windows API.
/// </summary>
/// <param name="libraryName">Name of the library.</param>
/// <param name="functionName">Name of the function.</param>
/// <param name="args">The arguments.</param>
/// <returns>True if function succeeds, otherwise false.</returns>
public static bool Invoke(string libraryName, string functionName, params int[] args)
{
/* Sanity checks. */
IntPtr hLoadLibrary = LoadLibrary(libraryName);
if (hLoadLibrary == IntPtr.Zero) return false;
IntPtr hGetProcAddress = GetProcAddress(hLoadLibrary, functionName);
if (hGetProcAddress == IntPtr.Zero) return false;
// Allocates more than enough memory for an stdcall and the parameters of a WinAPI function
IntPtr hMemory = VirtualAlloc(IntPtr.Zero, 1024 * 1024, MEM_COMMIT | MEM_RESERVE, MEM_EXECUTE_READWRITE);
if (hMemory == IntPtr.Zero)
return false;
IntPtr hMemoryItr = hMemory;
// Prepends the stdcall header signature
Marshal.Copy(new byte[] {0x55, 0x89, 0xE5}, 0, hMemoryItr, 0x3);
hMemoryItr = (IntPtr)((int)hMemoryItr + 0x3);
// Loop through the passed in arguments and place them on the stack in reverse order
for (int i = (args.Length - 1); i >= 0; i--)
{
Marshal.Copy(new byte[] {0x68}, 0, hMemoryItr, 0x1);
hMemoryItr = (IntPtr)((int)hMemoryItr + 0x1);
Marshal.Copy(BitConverter.GetBytes(args[i]), 0, hMemoryItr, 0x4);
hMemoryItr = (IntPtr)((int)hMemoryItr + 0x4);
}
Marshal.Copy(new byte[] {0xE8}, 0, hMemoryItr, 0x1);
hMemoryItr = (IntPtr)((int)hMemoryItr + 0x1);
Marshal.Copy(BitConverter.GetBytes((int)hGetProcAddress - (int)hMemoryItr - 0x4), 0, hMemoryItr, 0x4);
hMemoryItr = (IntPtr)((int)hMemoryItr + 0x4);
// Cleaning up the stack
Marshal.Copy(new byte[] {0x5D, 0xC2, 0x4, 0x0 /* <= I made a LOL. */}, 0, hMemoryItr, 0x4);
// Don't forget to increment if you are adding more ASM code here: hMemoryItr = (IntPtr)((int)hMemoryItr + 0x4);
try
{
var executeAsm = (RunAsm) Marshal.GetDelegateForFunctionPointer(hMemory, typeof (RunAsm));
executeAsm();
}
catch { return false; }
// Clean up the memory we allocated to do the dirty work
VirtualFree(hMemory, 0, MEM_RELEASE);
return true;
}
// ReSharper disable InconsistentNaming
private const uint MEM_RELEASE = 0x8000;
private const uint MEM_COMMIT = 0x1000;
private const uint MEM_RESERVE = 0x2000;
private const uint MEM_EXECUTE_READWRITE = 0x40;
// ReSharper restore InconsistentNaming
// My own sexy delegate:
[UnmanagedFunctionPointer(CallingConvention.StdCall, SetLastError = true)]
private delegate void RunAsm();
// WinAPI used:
[DllImport("kernel32.dll", SetLastError = true)]
private static extern bool VirtualFree(IntPtr lpAddress, UInt32 dwSize, uint dwFreeType);
[DllImport("kernel32.dll", SetLastError = true)]
private static extern IntPtr VirtualAlloc(IntPtr lpAddress, UInt32 dwSize, uint flAllocationType, uint flProtect);
[DllImport("kernel32.dll", SetLastError = true)]
private static extern IntPtr LoadLibrary(string lpFileName);
[DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Ansi)]
private static extern IntPtr GetProcAddress(IntPtr hModule, string lpProcName);
}
答案 0 :(得分：6)
您可以使用IntPtr.ToInt32方法吗？这应该适用于第一个参数。虽然不确定结构转换。
或许可以看一下this post关于如何将结构转换为整数的想法。
更新：
在C＃中没有直接的C＃等价的VarPtr，但我确实找到了一个引用here的手册（以及它正在做什么的解释......听起来类似于{{3中的VarPtr的解释） }}）。这是代码的摘录。它可能对您有用：
public static int VarPtr(object e)
{
GCHandle GC = GCHandle.Alloc(e, GCHandleType.Pinned);
int gc = GC.AddrOfPinnedObject().ToInt32();
GC.Free();
return gc;
}
注意：此功能存在一些潜在缺陷，如this post中所述。